The invention relates to a physiological-signal-analysis device, and particularly to a physiological-signal-analysis device having a plurality of electrode leads.
Acquiring a twelve lead ECG requires the attachment of ten electrodes to a patient. In a first attachment scheme, which is referred to herein as a resting or diagnostic attachment scheme, an attendant (e.g., a doctor, a nurse, an aide, a technician, etc.) places six electrodes on the patient""s chest and four electrodes on the patient""s limbs. The six electrodes across the chest are known as the V-electrodes (i.e., V1, V2, V3, V4, V5 and V6). The four electrodes attached to the limbs are known as right arm (RA), left arm (LA), left leg (LL) and right leg (RL) electrodes. For diagnostic ECGs the correct placement of the limb electrodes is on the limbs. That is, historically, the limb electrodes were placed at the end of the limbs (e.g., the RA electrode is placed at the right wrist, the RL electrode is placed at the right ankle, etc.). Currently, the limb electrodes are placed more proximal on the limbs.
In a second attachment scheme, which is referred to herein as a monitoring attachment scheme, the attendant places the limb electrodes on the patient""s torso. That is, the attendant places the limb electrodes at or proximal to the shoulders and hips. The monitoring attachment scheme includes schemes that are typically referred to as stress, exercise, activity compatible, torso, Mason-Likur, Lund, and/or Krucoff attachment schemes. Placing the limb electrodes onto the patient""s torso allows the patient to have more freedom of limb motion. Also, moving the electrodes off of the limbs reduces noise pickup from muscle activity of the limbs.
It has become well documented that ECGs recorded using the monitoring attachment scheme can be clinically different from ECGs recorded on the same patients using the diagnostic attachment scheme. These differences can mask real charges or introduce false changes when serial ECGs are compared. Accordingly, it would be beneficial to use an electrode placement that provides ECG recording as much like standard diagnostic ECGs as possible while providing the freedom of motion and reduction of artifact enjoyed by the monitoring attachment scheme.
Accordingly, the invention provides a placement scheme, which is referred to herein as an asymmetrical attachment scheme. For one embodiment of the asymmetrical attachment scheme, the attendant connects the six chest (i.e., xe2x80x9cVxe2x80x9d) electrodes on the patient""s chest as normally attached in prior schemes, attaches the right leg electrode on either the limb or the torso, attaches the left leg electrode and right arm electrode on the torso, and the left arm electrode on the limb.
Regardless which attachment scheme is used, occasionally, an attendant incorrectly attaches the electrodes to the patient, or incorrectly connects two or more lead wires to the wrong electrodes. For example, an attendant may incorrectly connect a lead wire to the wrong electrode. The physiological-signal-analysis device expects the lead to be connected to an electrode that is attached at a particular place on the patient""s body. This error is referred to herein as lead reversal. A second placement error occurs when the attendant places the electrodes on the wrong spot of the patient""s body. This error is referred to herein as a lead placement error. These problems result in the physiological-signal-analysis device acquiring inaccurate or unusable ECGs. Thus, it would be beneficial to have a device to assist the attendant in attaching the electrodes to the patient""s body in the correct location, and to assist the attendant in attaching the lead wires to the correct electrodes.
Accordingly, in one embodiment the invention provides a physiological-signal-analysis device including a lead set, and a central unit connected to the lead set. The lead set includes a plurality of electrodes connectable to a patient. Each electrode has a non-alphanumeric symbol that defines a placement of the electrode on the patient in relation to the other electrodes. The lead set further includes a plurality of lead wires. Each lead wire is connected to one of the electrodes, respectively, and has a symbol that defines the electrode connected to the lead wire.
In another embodiment, the invention provides a physiological signal electrode pack having a liner, and first and second electrodes connected to the liner. The first electrode has a first non-alphanumeric symbol, is removable from the liner, and is connectable to a patient. The second electrode has a second non-alphanumeric symbol, is removable from the liner and is connectable to the patient. The second non-alphanumeric symbol defines a placement of the second electrode on the patient in relation to the first electrode. Other embodiments, features and advantages of the invention will become apparent by consideration of the detailed description and accompanying drawings.